class_docstr: When called, this ensemble will return the mean prediction from the entire list of underlying mixers.
  
  NOTE: can only be used in regression tasks.
code: def __call__(
      self, ds: EncodedDs, args: PredictionArguments
  ) -> pd.DataFrame:
      predictions_df = pd.DataFrame()
      for mixer in self.mixers:
          predictions_df[f"__mdb_mixer_{type(mixer).__name__}"] = mixer(
              ds, args=args
          )["prediction"]
  
      return pd.DataFrame(
          predictions_df.mean(axis="columns"), columns=["prediction"]
      )
  
file_path: lightwood/lightwood/ensemble/mean_ensemble.py
imports: from typing import List, Optional
  import pandas
  from lightwood.mixer.base import BaseMixer
  from lightwood.ensemble.base import BaseEnsemble
  from lightwood.api.types import PredictionArguments
  from lightwood.data.encoded_ds import EncodedDs
  from type_infer.dtype import dtype
label_desc: Use image node_id 2 for calling the MeanEnsemble obj's underlying member method code with example usage: obj.__call__(ds, args) and returns: pd